In present day communications involving signal transmitting communication lines, several standardized interface connecting arrangements have been adopted for establishing electrical connections to the lines. One such interface is the miniature or modular jack, which has been adopted by the U.S. Federal Communications Commission as the standard connector for connecting telephone equipment to communications, i.e., telephone, lines. This jack, however, comes in different versions, depending upon the number of electrical contacts to be made, e.g., four, six, or eight. In addition, other connectors, such as coaxial connectors, exist for equipment other than telephones that share the same location at a customer's premises, but do not share the same interface standard. Because a large number of such non-standard connector types exists, individual and separate housings and wall plates are necessary to enable the customer to connect all of his or her communications equipment to the proper incoming and outgoing communications lines.
In U.S. Pat. No. 4,261,633, there is shown a jack frame molded into a wall plate as an integral part thereof. However, this arrangement has the disadvantage, as suggested hereinbefore, of requiting a different wall plate for each different jack, different plates being needed for jacks that differ from each other only slightly. U.S. Pat. No. 4,859,201 represents an improvement over the '633 patent in that it can accommodate a number of jack outlets where, conceivably, the jacks could be different from each other. However, the embodiments disclosed in that patent do not provide for easy and quick attachment and removal of the jacks to and from the wall plate. U.S. Pat. No. 5,096,439 of Arnett is directed to an arrangement for mounting a number of jacks to a single wall plate with a simple and convenient arrangement for attaching and releasing the jacks to and from the wall plate. Thus, it can be appreciated that the prior art, in the electrical communications area, has progressed to the point of accommodating multiple jacks in a single wall plate. However, there does not appear to be, in the prior art, any arrangement for accommodating both electrical wires and optical fibers in a single flush mounted wall plate. There are, in the prior art, arrangements using both electrical and optical connections. However, these arrangements are not flush mounted, generally requiring special boxes for containing the connections, which do not provide ready and easy access to the connectors. In part, this is a consequence of the very special handling and connecting limitations for optical fiber.
Optical fiber cables, more particularly single buffered fibers encased in a protective member, require extreme care in handling and in connecting, as well as positioning and storing. The fiber cannot be wound or bent to a radius less than a prescribed minimum without the occurrence of microcracks. Thus, it is important that some form of strain relief be used in routing the fiber. Further, it is desirable that the fiber be guided and supported to eliminate any loose fiber sags or loops that could, possibly, be inadvertently snagged or twisted, thereby risking damage to the fiber. In addition, the connection of the fiber to another fiber or to apparatus requires that the connector be capable of joining two optical fiber ends with a minimum of insertion loss and it must be mechanically stable while providing adequate protection to the junction between the fibers. There are, in the present state of the art, numerous types of optical fiber connectors in use, which are, for the most part, incompatible with each other and which vary as to size, shape and mode of connection. This problem is treated in U.S. Pat. Nos. 5,274,729 of King et al. and 5,238,426 of Arnett in the context of universal patch panels. In the King et al. patent, the patch panel has a plurality of differently sized and shaped openings for accommodating the mounting hardware, by means of build-outs, of a plurality of different optical connectors. The Arnett arrangement has a patch panel or plate having a plurality of substantially identical openings therein in which are mounted adapters for different types of optical couplers as well as electrical couplers. Neither patent deals with wall plates and the additional problems attendant thereto.
The standard wall plate functions as a cover for the commonly used NEMA (National Electrical Manufacturers Association) electrical outlet box, generally mounted to the rear of the wall. As such, the wall plate generally has one or more electrical jacks, with connecting wires being stored in the outlet box or passing therethrough, where necessary. Such an assembly is compact, efficient, and simple to use, the customer, for example, having only to plug a connector jack into its receptacle on the faceplate to complete the connection. However, the prior art, for the most part, does not address making the faceplate universal, i.e., accommodative of both electrical and optical fiber connectors, to the same degree that the universal patch panel has been fabricated. This stems, in part, from the care with which the optical fiber must be treated.
The care exercised in handling fibers is embodied, for example, in the SC connector, the general industry acceptance of which is increasing rapidly. Such a connector for connecting buffered fibers is shown and described in U.S. Pat. No. 5,212,752 of Stephenson, et al. An SC connector includes a ferrule assembly including a barrel having a collar at one end and an optical fiber terminating ferrule projecting from the barrel. The ferrule assembly is disposed in a plug frame such that an end portion of the ferrule projects from one end of the frame. The plug frame is configured to snap lock into a grip member, and the grip is inserted into one side of the coupler and locked thereto, while the corresponding grip of another SC connector is inserted into the other side of the coupler and locked. The coupler is dimensional such that when the two connectors are inserted therein, the ends of the ferrules abut each other to form a low insertion loss optical connection. When the SC coupler is to be mounted to a wall plate, for example, the plate incorporates a housing member into which the couplers are inserted, thus the body of the coupler extends outwardly from the surface of the wall plate.
In any such mounting of an optical fiber, there are certain restraints that must be observed which are aimed at protecting the fiber. Thus, there is a need for slack in the usually buffered optical fiber to allow for handling and routing without incurring too sharp bends in the fiber. The Electronics Industry Association Spec. 568A calls for at least one meter of fiber slack which may be stored on a storage spool, and a minimum bending radius of three quarters of an inch (3/4"). Thus, any wall mounting for optical fiber must be capable of meeting these constraints, which is difficult to realize where space is at a premium. These constraints on the optical fiber mode of connection have, apparently for the most part, deterred efforts to realize a universal faceplate flush mounting arrangement for both electrical and fiber connectors, especially where it is necessary or desirable to use the NEMA standard outlet box as a part of the outlet assembly.
Because of the rapidly growing use of both optical fibers and electrical wires and cables in the same milieu, attention has been directed more and more to the realization of some form of universal connector or outlet. There is in the prior art, for example, an arrangement for connecting both electrical wires and optical fibers to an outlet box which comprises a box or container consisting of a base plate and a cover plate, with the base plate adapted to be mounted on the front of the outlet box. The base plate provides for snap-in SC and ST connector modules (couplers) oriented vertically and opening toward the bottom sidewall of the faceplate. Within the volume defined by the base plate are pins and flanges for coiling the optical fibers within the volume with an acceptable bend radius. The faceplate has provision for housing electrical jacks wherein the wires therefrom are passed directly through the container to the outlet box. When assembled and mounted in place, the optical fiber connector modules are not readily visible and connection thereto is apparently achieved by feel. The cover is removable only by unscrewing and thus, ready access to the modules is not easily realized. The fiber is coiled somewhat loosely within the container and not well secured therein, and is stored on the room side of the wall, without the protection of the wall against damage. Thus, the prior art arrangement leaves much to be desired in overcoming the various problems encountered with universal connecting assemblies pointed out heretofore.